using-aiohttp.py

import io
import asyncio
import aiohttp
import nest_asyncio

nest_asyncio.apply()


async def fetch_dataframe(session, url):
    """ Asynchronously fetches a csv file using the url """
    async with session.get(url) as response:
        byte_code = await response.content.read()
        df = pd.read_csv(io.BytesIO(byte_code), encoding='utf8')
        return df


async def fetch_concurrent(urls):
    """ Makes concurrent calls """
    loop = asyncio.get_event_loop()
    async with aiohttp.ClientSession() as session:
        tasks = []
        for url in urls:
            tasks.append(loop.create_task(fetch_dataframe(session, url)))

        all_dfs = []
        # Loop through each completed task
        for df in asyncio.as_completed(tasks):
            df = await df
            all_dfs.append(df)

        # Concatenate all fetched dataframes into one
        return pd.concat(all_dfs, ignore_index=True)